The overall goal of this Academic Career Award resubmission is to support the development of new techniques for the improvement of muscle strength and functional ability of the frail elderly. The research component of this study will evaluate the impact of growth hormone supplementation and a home exercise program on the strength of older individuals receiving knee replacement surgery. This will be done through the use of a double-blind randomized clinical trial. In addition to muscle strength, other outcomes to be measured include thigh muscle area, vertebral bone density, fat and lean body mass, gait speed and psychological status. The research training portion of this award emphasizes the development of knowledge in exercise and sports science, body composition measurement, and endocrinology through formal course work at the University of Arizona and short-term intensive study of clinical trial design and analysis at the University of Michigan. The clinical and teaching component of this grant involves working with residents and fellows one half day per week in an outpatient geriatric assessment unit, and limited attending on the inpatient consultation service and university-affiliated academic nursing home. Development of a research oriented mobility disorders clinic will also be a goal of the proposal. Support is requested primarily for 70 percent protected research time, but this award will also strengthen geriatric teaching and clinical programs at the University of Arizona College of Medicine.